Income Taxes (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2021	Dec. 31, 2020
Non-Current Regulatory Liabilities	$ 1,247.7	$ 1,188.9
OG&E [Member]
Non-Current Regulatory Liabilities	1,247.7	$ 1,188.9
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	97.7
OGE Energy [Member]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	$ 6.6

Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to increase (decrease) in the income tax rates.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=123427490&loc=d3e32059-109318

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration